2 files changed, 54 insertions, 5 deletions

diff --git a/src/Network/BitTorrent/Core/Node.hs b/src/Network/BitTorrent/Core/Node.hs
index 0cb95dd2..f6ab7d82 100644
--- a/src/Network/BitTorrent/Core/Node.hs
+++ b/src/Network/BitTorrent/Core/Node.hs
@@ -1,4 +1,21 @@
+-- |
+--   Module      :  Network.BitTorrent.Core.Node
+--   Copyright   :  (c) Sam Truzjan 2013
+--                  (c) Daniel Gröber 2013
+--   License     :  BSD3
+--   Maintainer  :  pxqr.sta@gmail.com
+--   Stability   :  experimental
+--   Portability :  portable
+--
+--   A \"node\" is a client\/server listening on a UDP port
+--   implementing the distributed hash table protocol. The DHT is
+--   composed of nodes and stores the location of peers. BitTorrent
+--   clients include a DHT node, which is used to contact other nodes
+--   in the DHT to get the location of peers to download from using
+--   the BitTorrent protocol.
+--
 {-# LANGUAGE RecordWildCards            #-}
+{-# LANGUAGE FlexibleInstances          #-}
 {-# LANGUAGE TemplateHaskell            #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE DeriveDataTypeable         #-}
@@ -22,23 +39,29 @@ import Data.Bits
 import Data.ByteString as BS
 import Data.BEncode as BE
 import Data.Default
+import Data.IP
+import Data.List as L
 import Data.Ord
-import Data.Typeable
 import Data.Serialize as S
+import Data.String
+import Data.Typeable
 import Data.Word
 import Network
 import System.Entropy
 
 import Data.Torrent.JSON
-import Network.BitTorrent.Core.PeerAddr ()
+import Network.BitTorrent.Core.PeerAddr (PeerAddr (..))
 
 {-----------------------------------------------------------------------
 --  Node id
 -----------------------------------------------------------------------}
 -- TODO more compact representation ('ShortByteString's?)
 
--- | Normally, /this/ node id should we saved between invocations of
--- the client software.
+-- | Each node has a globally unique identifier known as the \"node
+-- ID.\"
+--
+--   Normally, /this/ node id should we saved between invocations
+--   of the client software.
 newtype NodeId = NodeId ByteString
   deriving (Show, Eq, Ord, BEncode, FromJSON, ToJSON, Typeable)
 
@@ -55,6 +78,13 @@ instance Serialize NodeId where
   put (NodeId bs) = putByteString bs
   {-# INLINE put #-}
 
+-- | ASCII encoded.
+instance IsString NodeId where
+  fromString str
+    | L.length str == nodeIdSize = NodeId (fromString str)
+    |           otherwise = error "fromString: invalid NodeId length"
+  {-# INLINE fromString #-}
+
 -- | Test if the nth bit is set.
 testIdBit :: NodeId -> Word -> Bool
 testIdBit (NodeId bs) i
@@ -85,7 +115,9 @@ $(deriveJSON omitRecordPrefix ''NodeAddr)
 -- | KRPC compatible encoding.
 instance Serialize a => Serialize (NodeAddr a) where
   get = NodeAddr <$> get <*> get
+  {-# INLINE get #-}
   put NodeAddr {..} = put nodeHost >> put nodePort
+  {-# INLINE put #-}
 
 -- | Torrent file compatible encoding.
 instance BEncode a => BEncode (NodeAddr a) where
@@ -94,6 +126,19 @@ instance BEncode a => BEncode (NodeAddr a) where
   fromBEncode b = uncurry NodeAddr <$> fromBEncode b
   {-# INLINE fromBEncode #-}
 
+-- | Example:
+--
+--   @nodePort \"127.0.0.1:6881\" == 6881@
+--
+instance IsString (NodeAddr IPv4) where
+  fromString = fromPeerAddr . fromString
+
+fromPeerAddr :: PeerAddr a -> NodeAddr a
+fromPeerAddr PeerAddr {..} = NodeAddr
+  { nodeHost = peerHost
+  , nodePort = peerPort
+  }
+
 {-----------------------------------------------------------------------
 --  Node info
 -----------------------------------------------------------------------}
@@ -108,7 +153,10 @@ $(deriveJSON omitRecordPrefix ''NodeInfo)
 instance Eq a => Ord (NodeInfo a) where
   compare = comparing nodeId
 
--- | KRPC 'compact list' compatible encoding.
+-- | KRPC 'compact list' compatible encoding: contact information for
+-- nodes is encoded as a 26-byte string. Also known as "Compact node
+-- info" the 20-byte Node ID in network byte order has the compact
+-- IP-address/port info concatenated to the end.
 instance Serialize a => Serialize (NodeInfo a) where
   get = NodeInfo <$> get <*> get
   put NodeInfo {..} = put nodeId >> put nodeAddr
diff --git a/src/Network/BitTorrent/Core/PeerAddr.hs b/src/Network/BitTorrent/Core/PeerAddr.hs
index 86b88491..63ae04b9 100644
--- a/src/Network/BitTorrent/Core/PeerAddr.hs
+++ b/src/Network/BitTorrent/Core/PeerAddr.hs
@@ -1,4 +1,5 @@
 -- |
+--   Module      :  Network.BitTorrent.Core.PeerAddr
 --   Copyright   :  (c) Sam Truzjan 2013
 --                  (c) Daniel Gröber 2013
 --   License     :  BSD3